1 Air Fleet was organized
on 10 April 1941 at the instigation of Combined FleetcommanderYamamoto Isoroku. The
brilliant air officer of Carrier Division 1,
Genda Minoru, had advocated such a move for five years, but Yamamoto
hisitated at first because of the profound change it implied in Navy
doctrine. The idea was further championed by Ozawa Jisaburo, who formally
submitted it to Yamamoto and the Navy
General Staff in April 1940. Yamamoto was angered by the breach of
protocol but finally endorsed the proposal in December 1940.

1 Air Fleet was an
important tactical innovation,
concentrating
Japan's first-line naval air power into a
single independent force rather than assigning it to provide air cover
for the battle line. It was organized a few months before the attack on
Pearl Harbor
and
intensively trained for that
mission. Some of its destroyers
were
assigned to missions intended to clear the return path to Japan after
the attack. 1 Air Fleet was not a balanced force, however, and it always operated with heavy surface escort provided by 1 and 2 Fleets.

Curiously, neither the commander of 1 Air Fleet, Nagumo Chuichi; his chief of
staff, Kusaka Ryunosuke;
nor his senior staff officer, Oishi Tamotsu, were aviators. However, the air
officer was Genda, upon whom Nagumo came to heavily rely.